Zanuck, the son of late legendary 20th Century Fox studio mogul Darryl F. Zanuck and patriarch of his own budding filmmaking dynasty, is a producer on both movies.

Zanuck produced "The Road to Perdition" with one of his grown sons, Dean, and the film's director, Oscar winner Sam Mendes. On "Reign of Fire," Zanuck joined his wife, noted filmmaker Lili Fini Zanuck, in producing duties along with Spyglass Entertainment Group co-chairmen Gary Barber and Roger Birnbaum.

So is this a rare case of a producer watching one of his movies cannibalize the other? Not necessarily, say Hollywood observers.

"Reign of Fire" is a PG-13-rated summer-popcorn film about fire-breathing dragons terrorizing present-day London, said box-office tracker Paul Dergarabedian, while "The Road to Perdition" is an Oscar-caliber, R-rated film starring Tom Hanks as a mob hit man.

"There are many more dissimilarities to these movies than similarities, so they are not really competing against each other," said Dergarabedian, the president of Exhibitor Relations Co. "It just so happens they are hitting the marketplace simultaneously, but they shouldn't be concerned that these films are going to cannibalize each other since they are chasing two entirely different types of audiences."

Still, it is rare that two studios pick the same release date when producers are as prominent as Zanuck and his wife, whose 1989 film, "Driving Miss Daisy," won the Academy Award for best picture.

"I don't think anyone would want to make them mad," Dergarabedian said.